Thanks for the reply. Performance and ease of use are two of the criteria we're attempting to evaluate so your experience is very timely.

We're engaged in a consolidation project for several clients and are considering using mount points to increase the number of instances being hosted on a server/cluster (to mitigate the problem of not having enough drive letters for the physical volumes involved) and, where the customer wants to host databases for multiple applications onto one instance, isolate storage usage so that any one set of application databases does not cause problems for other application databases when unexpected storage usage event (e.g. from an INSERT/UPDATE/DELETE query using up all of the transaction log space) occurs. Using mount points would also give us the flexibility to add space easily.

The SAN guys told me that for disk performance the read/write I/O for SQL and Exchange where quite similar in patterns. But Fileshares where not so they tended to isolate Fileshares on own LUN's(DiskZones) and didn't use Mount points for those. Somehow they had experienced that performance-wise the mountpoints didn't deliver. In Exchange and SQL group we couldn't tell if dedicated disk with driveletter or mounthpoint - we used this scenario for sharepoint databases and when users are using browser expectations of performance drops quite significantly. I guess it's more dependandt on SAN design than on Windows/SQL performance.

I don't have any problems with translog growth. I normally tune the size of the translog the first month a new db comes into an instance. Monitor log backup size on the database and then adds about 40% for growth on the log file and set it to fixed. Only challenge I have is tempdb and unexpected behaviour when adding new db's.